We had two sightings of blue-ringed octopus this week – one at the sunken plane and the other on the house reef of Turtle Bay Dive Resort

The blue-ringed octopuses are currently recognized as one of the world's most venomous marine animals. Despite their small size and relatively docile nature, they can prove a danger to humans. They can be recognized by their characteristic blue and black rings and yellowish skin. When the octopus is agitated, the brown patches darken dramatically, and iridescent blue rings or clumps of rings appear and pulsate within the maculae. Typically 50-60 blue rings cover the dorsal and lateral surfaces of the mantle. They hunt small crabs, hermit crabs, and shrimp, and may bite attackers, including humans, if provoked.

An individual blue-ringed octopus tends to use its dermal cells to camouflage itself until provoked, at which point it quickly changes color, becoming bright yellow with blue rings or lines.

Their diet typically consists of small crab and shrimp, but they may also feed on fish if they can catch them. They pounce on their prey, paralyze them with venom and use their beaks to tear off pieces. They then suck out the flesh from the crustacean's exoskeleton

Blue-ringed octopus females lay only one clutch of about fifty eggs in their lifetime towards the end of autumn. Eggs are laid then incubated underneath the female's arms for approximately six months, and during this process she does not eat. After the eggs hatch, the female dies, and the new offspring will reach maturity and be able to mate by the next year.

The blue-ringed octopus is 12 to 20 cm (5 to 8 inches), but its venom is powerful enough to kill humans. There is no blue-ringed octopus anti-venom available. The blue-ringed octopus, despite its small size, carries enough venom to kill 26 adult humans within minutes. Furthermore, their bites are tiny and often painless, with many victims not realizing they have been envenomed until respiratory depression and paralysis start to set in.